The invention relates to Francis-type hydraulic machines (i.e., turbines, pump-turbines and pumps) which employ rotors of large diameter.
In known machines of this kind, the rotor consists of a bladed wheel, such as an impeller or runner, and a shaft, and the shaft is mounted on the machine foundation. In installations where bladed wheels of very large diameter are used, it is difficult to center the rotor reliably and to mount it so as to be free from vibrations.
The object of this invention is to provide an improved Francis-type hydraulic machine in which the rotor is mounted in a reliable and satisfactory manner, even in cases where the bladed wheel has a large diameter. According to the invention, this object is achieved by providing bearing apparatus for the rotor which is arranged in a peripheral region of the bladed wheel spaced radially from the axis. Preferably, the bearing apparatus includes an annular surface carried by the bladed wheel, and cooperating bearing shoes which are mounted on the machine foundation by means of servomechanisms which serve to adjust the shoes relatively to said surface.